/Engine/Source/Runtime/UMG/Public/Blueprint/UserWidget.h
void DuplicateAndInitializeFromWidgetTree ( [UWidgetTree](API\Runtime\UMG\Blueprint\UWidgetTree) * InWidgetTree, const [TMap](API\Runtime\Core\Containers\TMap)< [FName](API\Runtime\Core\UObject\FName), [UWidget](API\Runtime\UMG\Components\UWidget) * > & NamedSlotContentToMerge )